1. Technical Field
The present invention relates to stereoscopic imagery and more particularly, to a method for displaying a stereoscopic image and a display apparatus for performing the method.
2. Discussion of the Related Art
Generally, a display apparatus displays two-dimensional images (hereinafter referred to as 2D images). Recently, according to increasing demand for the display of three-dimensional images (hereinafter referred to as 3D images) in fields of games, movies and so on, display apparatuses for displaying 3D images have been developed.
A 3D image display apparatus displays a 3D image by using binocular parallax, which is the process of directing two distinct images to the left and right eyes of the observer. By directing a left-eye image to the left eye of the observer and a right-eye image to the right eye of the observer, the observer is able to perceive a sense of depth.
The 3D image display apparatus using the binocular parallax may be characterized as either a stereoscopic-type display apparatus or an auto-stereoscopic-type display apparatus according to whether specific glasses are necessary to properly view the 3D display device. The stereoscopic-type display apparatus may be characterized as either a passive polarized glasses-type display apparatus, an active shutter glasses-type display apparatus, etc. In the passive polarized-type display apparatus, a pair of glasses having different polarizing axes is used by a user. In the active shutter glasses-type display apparatus, display of a left-eye image and a right-eye image are alternated, and a pair of glasses in which a left-eye shutter and a right-eye shutter are closed and opened in synchronous with the alternating display is used. According to the active shutter glasses-type display apparatus, the left-eye shutter or the right-eye shutter is opened during a vertical blanking interval after the left-eye image or the right-eye image is displayed on a display panel, and then the left-eye image or the right-eye image may be viewed by the observer.
Many LCD display devices are capable of displaying image frames at a rate of 60 image frames per second (60 Hz). Thus, the left-eye and right-eye images are respectively provided at a frequency of approximately 30 Hz when a 3D stereoscopic image is displayed through a conventional LCD device. At such a display frequency, the observer may become aware of a change process from the left-eye image into the right-eye image or a change process from the right-eye image into the left-eye image. Other LCD display devices are capable of displaying 120 image frames per second (120 Hz). In such high-driving frequency devices, left-eye and right-eye images are respectively provided at a frequency of approximately 60 Hz when a 3D stereoscopic image is displayed. Accordingly, the left-eye image and the right-eye image co-exist and crosstalk in which the left-eye image influences what is seen by the right eye, and vice versa, may be generated.
Since the LCD apparatus is driven using a progressive scan method, points of time for applying a line data to a plurality of horizontal lines of the LCD apparatus are different from each other and liquid crystal responses for a same point of a time are different from each other. Thus, when a 3D image is displayed on a screen of the LCD apparatus by alternately displaying a left-eye image and a right-eye image, crosstalk is generated due to a gradation difference between the left-eye image and the right-eye image and a display timing of the left-eye image and the right-eye image in accordance with the progressive scan method. Particularly, since a response speed is slow from an upper portion of the display panel to a lower portion of the display panel, crosstalk may be generated at the lower portion of the display panel rather than the upper portion of the display panel. Accordingly, a display quality of the stereoscopic image may be decreased due to crosstalk.